Treatment of hydrocarbons



June 7, 1932. RAY 1,862,507

TREATMENT OF HYDHOCARBONS Filed June 26, 1926 3 Sheets-Sheet 1 June 7, 1932. GRAY 1,862,507

TREATMENT OF HYDROGARBONS Filed June 26, 1926 5 Sheets-Sheet 2 %& a

anvenbbz June 7, 1932. 'r. 'r. GRAY TREATMENT OF HYDROCARBONS 3 Sheets-Sheet 3 Filed Juna 26, 1926 p anwmtoz 85 giro M40412 W Patented June 7, 1932 UNITED STATES PATENT OFFICE THOMAS T. GRAY, OI ELIZABETH, NEW JERSEY, ASSIGNOR TO THE GRAY PROCESSES CORPORATION, OF NEWARK, NEW JERSEY A CORPORATION 01' DELAWARE TREATMENT OF HYDROCABBONS Application filed June 26,

This invention relates to the treatment of hydrocarbon compounds and the like, particularly in the distillation thereof, to produce stable commercial liquids of good odor and permanent water white color. It is capable of use in connection with many substances, a particularly important use being in the production of gasoline from heavy oils by cracking.

An object of my invention is a simple and efficient apparatus for subecting hydrocarbon vapors to the action of a treating material under circumstances most favorable for effective action, either in a separate distilla-. tion process or as a part of an original distillation or cracking process.

At the present time, the gasoline, naphtha or benzine fractions existing naturally in most crude petroleums do not require treatment after distillation in order to make them commercially satisfactory, unless they are unstable or happen to contain a relatively high amount of sulphur, in Which case the usual practice is to treat these fractions in the usual way with sulphuric acid followed by an alkaline solution of sodium plumbite. But with the extension of the use of the cracking process to produce low boiling point fractions. new problems of purification have arisen for which "arious solutions have been offered. The cracked hydrocarbon distillates resulting from the distillation of heavy oils at high temperatures, which may be colorless when fresh, contain unsaturated hydrocarbons not present in the original material treated, or in the crude petroleum from which the original material treated was obtained. Certain of these hydrocarbons are VBILV unstable, possessing the property of combining between themselves to form new compounds of considerably higher boiling point, called polymers, and the process of this combination is termed polymerization. Under rdinary circumstances, polymerization takes place slowly. It efl'ects discoloration of the 1926. Serial No. 118,621.

of constituents of the distillate with the acid in formin sludge acid. Nextilthere is a loss in low-boi ing compounds of t e sort desired to be obtained by the treatment, robably because of polymerization induce by the presence of the acid. Further, the acid reacts with certain of the hydrocarbons to form esters which are not removed by later Washings and which break down on combustion in a motor with the liberation of sulphur dioxide which is very corrosive to the piston heads and cylinder walls. Finally, the acid treatment is diflicult, dangerous and expensive to carry on and produces ofl'ensive waste products.

In my Patent Number 1,340,889, granted May 25, 1920, I have disclosed that purification of such compounds may be accomplished by passing the vapors of distillation into contact with a catalyst such as fullers earth,

bone-black, or the like, while the same is at.

a temperature substantially the same as that of the vapors. Polymerization of certain of the unsaturated compounds in the vapors takes place as the vapors come in contact with the catalyst. The polymers being of higher boiling point than the temperature of the catalyst, appear in liquid form in the catalyst and may be separated from the vapors. The vapors pass through the container of the catalyst to a condenser where they yield a finished product of improved odor, water-white color, not contaminated by any of the objectionable constitutents occurring in the product of the acid treatment, and free of objectionable unstable constituents. The desirable low-boilin compounds which would have been remove in the acid treatment, as above stated, are not removed during treatment in accfirdance with my invention but appear in t e condensate of the vapors. My invent-ion accordingly results in selective polymerization by removing the objectionable or unstable unsaturates without affecting the unobjectionableconstituents of the vapors. The polymers formed in the operation of my invention frequently resemble lubricating oils in physical tests but the iodine absor tion is considerably in excess of that of or inar lubricating oil. They frequently have a boi ing point considerably higher than that of the highest boiling fraction of the hydrocarbon products being treated, thus indicating that they could not have existed in the hydrocarbon productsbeing treated and that they must constitute a new composition of matter resulting from the process.

A comparison of certain features of old urifyin processes with the process of purication a ove set forth makes the latter clearer and more definite. The dark colored mineral oils which were produced by processes of distillation practiced shortly after the finding of petroleum in commercial quantities are evidently similar to those reduced oils which are at present filtered in the liquid state throu h fullers earth to effect dec'olorization in t e production of lubricating oils of red or pale amber color. Such oils did not contain the objectionable unsaturated constitutents that are found in distillates produced by present cracking processes. The exact composition of the coloring matter eliminated is not known but it is asphaltic physically and solid at ordinary temperature. The coloring matter removed from such oils through treatment in the liquid mass as described is retained by the fullers earth thereby indicating that it is insoluble in such oil under these circumstances. Such coloring matter can be partly removed fromthe fullers earth by extraction .with ether, benzol and alcohol and can be more completely removed by acidified alcohol. However, the introduction of cracking processes has produced distillates entirely different in character from products known in those earlier stages of the art of petroleum treatment. Such distillates contain highly unstable unsaturated hydrocarbons that do not exist in crude petroleum. There is a general belief that the unstable, unsaturated hydrocarbons that occur in such distillates are diolefins and it is the unstable characteristic of these hydrocarbons that renders them objectionable.

.It is'these unstable constituents that darken upon exposure to light, that oxidize to form an aldehydic group,

compounds containing and that de it soli colored matter. The

cracked distillates may be of very light color,

eeann? gasoline produced by crackin often being of satisfactory color. The ob ection to such distillates is not in the color of the original )roduct but lies in the reactivit of the obectionable, unstable, unsaturate compounds that give ofl'ensive odors and form gummy deposits in storage and carbureting apparatus and that, as to burning oils, char wicks of lamps. The catalyst herein referred to causes reaction within the vapors produced by cracking distillation and effects formation of color-producing compounds and thereafter effects their removal.

A characteristic of the present invention is that the polymers separated out of the vapors by the action of the catalyst may contain more dark coloring matter in the aggregate than was present in the vapors Just prior to their comin in contact with the catalyst, thus indicating t at new hydrocarbon compounds have been formed in the process. A part of this dark coloring matter may be held in the catalyst (if. it have sufficient adsorptive power, as in the case of fullers earth) while the remainder is carried off with the liquid polymers.

According to the present invention, the appa ratus for subjecting hydrocarbon vapors to the action of the treating material comprises a container within which treating material is supported upon a shelf or the like which is pervious to liquid and vapor hydrocarbons but im ervious to the treating material. Hydrocar on vapors to be treated are supplied to the container, preferably from a fractionating device, so that the vapors are brought intocontact with the treating material which is thereby heated and kept at the vaporizing temperature of the desired product by heat derived from the vapors themselves. Means are provided by the regulation of which the vapor may be maintained at atmospheric or any desired superatmospheric pressure during contact with the treating material. After treatment. the vapors are conducted to a condenser where they are converted into liquid. Means may be provided to bring the vapors into heat exchange relation to the treating material before being brought into actual contact therewith. The subjection of the vapors to treating material may result in the formation of hydrocarbons of higher boiling point than that of the desired product. Such hydrocarbons form in the treating material in liquid form and permeate therethrough to escape into the bottom of the container. Also there may be some condensation. at least until the treating material is thoroughly heated, of the desired fraction which will likewise collect in the bottom of the container. The liquid thus collected is returned by a reflux pipe to the system for re-vaporization at least of the desired fraction. This apparatus is particularly adapted to the subjection of cracked vapors to a catalyst are collected in the bottom of the con-.

tainer with any other condensate and refluxed back into the system. In the treat ment of an end point fraction supplied from a fractionator, the liquid collecting in the bottom of the container is preferably refluxed to the fractionator where the fraction is again vaporized.

Suitable forms of apparatus for carrying on my invention are shown in the accompanying drawings in which Figure 1 discloses partly in section one form of apparatus embodying the invention;

Fig. 2 is an enlarged detail of a portion of the treating tower;

Fig. 3 discloses a modified form of treating tower;

Fig. 4 discloses another modification of the treating tower and Figs. 5, 6, 7 and 8 disclose modified forms of apparatus embodying the invention.

Referring now to Figs. 1 and 2, 10 is a still to which crude oil is supplied through pipe 11 and from which vapors are discharged through the pipe 12 to a fractionating device 13. A pipe 14 leads from the topof the fractionator 13 to a treating tower 15 within which is provided a cylindrical partition 16 having apertures at its upper end in which are provided screens 17. A funnel shaped shelf 18 is supported from the interior of the partition 16 and terminates in a spout 19 which communicates through a valve 20 with a discharge pipe 21. Portions of the shelf 18 are cut away to provide a cellular structure and the apertures thus formed are closed by screens 22 removably supported by the shelf. These screens are of such size that they may be introduced or removed through the char in manhole 23 at the top of the tower. re erably the screens extend only over the lower portion of the shelf, the upper portion being left solid. A layer of mineral wool or the like may be laid over the screens 22 and upon it is placed the treating mate; rial 24. The reflux pipe 25 leads from the annular chamber of the treating tower to the upper part of the fra'ctionating device 13 and a similar refiux'pipe 26 leads from the bottom of the central chamber of the treating tower to a lower point in the fractionator 13. A pipe 27 leads from the bentral chamber at a point below the shelf 18 through a valve 28 to a condenser 29. By regulation of the valve 28, the vapor in the tower may be maintained at atmospheric or superatmospheric pressure as desired. A reflux pipe 30 leads from the bottom of the fractionator 13 to a pump 31 by means of which liquid in the bottom of the fractionator is returned to the inlet pipe 11 through the pipe 32. A pipe controlled by valve 3011 leads from the pipe 30 and a valve 32a is provided so that unvaporized residuum may be withdrawn from the still.

In operating this device to produce gasoline or the like from petroleum the crude oil is passed through the coil of the. still 10 where it is heated and distilled under pressure by regulating the valve 28. The vaporized cracked products are fed to the fractionator 13 where the heavier fractions are condensed and from which there is discharged through the pipe 14 to the annular chamber of the tower 15 a fraction having a definite boiling range, which fraction may be gasoline. The condensate in the fractionator 13 is returned to the still for redistillation. The fraction supplied to the treating tower passes through the screens 17 and into contact with the treating material 24 which in this instance is a catalytic agent such for example as fullers earth. In order to escape from the central chamber the vapors necessarily pass through the treating material and out through the pipe 27 to the condenser 29. The fixed gases go off by ipe 33 and the finished product is collecte in liquid form in the tank 34. After a period of operation the catalyst in the container commences to be wetted at the top due to the formation there of polymers of higher boiling point than the temperature of the vapors. This wetness increases progressively toward the bottom of the catalyst as the distillation continues until the. polymers pass with the vapors through the screen 22 into the bottom of the middle chamber. The polymers, being liquid, flow out of the container through the pipe 26 and are introduced into the fractlonator 13. There may be some condensation of the desired product in the catalyst and this also collects in the bottom of the central chamber from which it is refluxed to the fraotionator,

The vapor in its passage throughthe an-' nular chamber serves to heat the catal st I in the central chamber and some condensation may take place in this chamber. Such con densate is returned to the fractionator through the pipe 25. The screens '17 prevent the catalyst in the tower from being drawn through the apertures at the top of the partition 16 into the annular chamber under the influence of the vacuum created in the still when the latter is allowed to cool after a run has been made. Because of the fact that the upper portion of the shelf 18 is imperforate the vapors to be treated are forced to traverse a considerable depth of treating material before they can escape from the treating chamber.

In Figures 3 and4, there are disclosed treating towers in which the va or to be treated is passed directly from the' ractiona tor into contact with the treating material. In these figures, the treating tower 40 is provided with a covering 41 of heat insulating material in order that the heat of the vapors may be retained and imparted to the treating material with as small loss as possible. Within the tower 40 is supported a perforated shelf 42 over which may be laid a layer of mineral wool or metal screen and upon which is arranged the treating material 43. The vapor from the fractionator is introduced into the tower through the pipe 44 and discharged through the pipe 45, these pipes communicating with the tower on opposite sides of the shelf 42 so that the vapor to be treated has to pass through the treating material in order to escape from the container. A reflux pipe 46 leads from the bottom of the tower to the fractionator and the shelf 42 is provided with a spout 47 communicating with a discharge conduit 48 through a valve 49.

The fractionating tower may deliver the vapor to be treated to the treating tower under substantially uniform conditions of temperature and pressure thereby rendering very efiicient the action of the treating material. Such of the desired vapors as are condensed in the treating tower are returned to the system for revaporization so that the maximum yield is obtained.

Referring to Fig. 5, the pressure still 55, set in brickwork, is heated by tire or otherwise in the usual manner. It is connected by vapor line 56 to a port near the bottom of a dephlegmator tower 57. Within the dephlegmator is mounted a catal st container 58 which is open at the top, thereby communicating with the interior of the dephlegmator, and is provided at its bottom with a restricted neck portion 59 which communicates with a separating chamber 62 mounted within the lower portion of the dephlegmator. A return line 60 leads from the foot of the dephlegmator to the still 55. A second vapor line 61 leads from a point above the bottom of the separating chamber 62 to a condenser 63 and tank 65. A pipe 66 leads from the foot of the chamber 62 to a three-way valve 67, one connection, 68, from which leads back to the still and the other, 69, to a cooler 70 and tank 71. A vent pipe 72 may be provided for separating the fixed gases from the condensate at the foot of the condenser. Valves may be provided for the pipes 61, 68, 69 and 72. By means of the valve in the pipe 61, the vapor in the tower may be maintained at atmospheric or super-atmospheric pressure as desired. The catalyst container 58 within the dephlegmator 57 is provided with a wire netting partition 73 just above the neck 59, and upon this is placed a layer of mineral wool 76 or metal screen, or the like, after which the upper portion of the container is filled with fullers earth or the on like. Manholes 74 and 75 are preferably provided for the purpose of charging and discharging the container 58.

If it is desired to collect the polymers, the three-way valve may be set to lead them into the pipe 69 and so to the tank 71. Otherwise, they may be returned to the still 55 by pipe 68.

In Fig. 6 there is shown a somewhat modified apparatus adapted to carry out the process. Here the vapor line 86 from the still 85 enters the dephlegmator 87 near the top of the same. The catalyst container 88 is sealed at its top to the upper portion of the dephlegmator, so that the only communication bea tween the interior of the dephlegmator 87 and the catalyst container 88 is through the restricted neck portion 89 at the foot of the catalyst container. 'The pipe 91 is the vapor line from the catalyst container 88 to the condenser not shown. In this figure the vapors passing into the dephle mator from the pipe 86 pass around the cata yst container 88 and to the bottom thereof, and enter through the neck 89 and so come in contact with the heated catalyst within the container 88. The polymers formed in the catalyst within the container 88 dri down through the neck 89, where they join the liquids condensed out of the vapors in the dephlegmator and return to the still 85 through the return pipe 90.

Fig. 7 shows a somewhat modified apparatus in which the vapor pipe 96 from the still 95 introduces the vapors near the foot of the dephlegmator. The catalyst container 98 within the dephlegmator is provided with three openings: an inlet opening at the top of the container, a vapor outlet 101 adjacent the bottom of the catalytic material in the container, and a liquid outlet pipe 99 preferably leading to a cooler and tank, not shown, Where the polymers formed in the catalyst are collected. The products of condensation in the dephlegmator are returned to the still by the pipe 100.

In Fig. 8 I have shown a modified apparatus which makes it possible for the vapors to expand as they pass through the catalytic material. Here the vapor line 106 from the still 105 enters the dephlegmator 107 at a point about opposite the lower end of the catalyst container or chamber 108. The upper end of the chamber 108 communicates with the. interior of the dephlegmator 107 by means of a pipe 110 provided with a valve 111. The catalyst container 108 communicates at its lower end by a pipe 109 with a separating chamber 112 which is preferably located within the dephlegmator 107. Pipe 113 is rovided to convey the vapors from separating chamber 112 to any suitable condenser not shown. Pipe 114 is adapted to convey the liquids to a polymer tank not shown. The liquids condensed out of the vapors in the dephlegmator 107 are returned to the still 105 through the return pipe 115. In this type of apparatus the valve 111 may be regulated to produce desired pressure within the still and dephlegmator while allowing vapors to pass through the chamber 108 at reduced ressure. Valves 116 and 117 in pipes 113 and 114 respectively may be emgloyed to control the pressure in the cham- I have found that by the use of my invention in connection with cracking under pressure, I am able to obtain a yield of gasoline condensate which is substantially in excess of the yield of condensate obtained by a similar run under pressure but without using a catalyst. I do not explain this but believe it may be the result of a combination of certain of the uncondensable gases present in the vapors forming new compounds which are condensable under the conditions existing. But whether the invention be used to contact the vapor with the treating material at atmospheric or super-atmospheric pressure,.I am able to obtain a yield of condensate of commercial quality in excess of the yield from similar material by the sulphuric acid method of treatment, due to the fact that my method removes only the undesirable constituents, whereas the sulphuric acid method attacks certain of the desirable hydrocarbons as well. My present apparatus is a great improvement over prior devices, as it may be inserted in the existing apparatus of a distillation plant with the requirement of but few additional parts and no additional attention in operation. It obviates the necessity for large expenditure for machinery and equipment and produces a product that is better than has heretofore been commercially achieved.

In describing my invention by reference to its use in the purification of distillates made by the cracking process, I am merely illustrating one important use thereof. The invention may also be utilized to stabilize distillates other than cracked distillates such as the straight run distillate from some crude oilsffor example, certain oils occurring in California which on distillation alone yield unstable products. The invention is capable of a variety of similar uses where improved catalytic action is desired. It may, for example, be employed with appropriate modifications where two or more vapors are brought together and combined in the presence of a catalyst, or it may be used with other than catalytic materials in place of the catalyst. It will be understood, therefore, that the foregoing description and drawings are merely for the purpose of illustrating my invention, not of limiting it, and that many changes may be made within the meaning of the appended claims without departing from my invention- This application is a continuation in part of the application of T. T. Gray, Serial #664,893, filed September 26, 1923.

1. In an apparatus of the character de scribed, a still, a dephlegmator for receiving vapors from the still, a tower, means within said tower to support for free drainage treating material capable of polymerizingunstable unsaturated hydrocarbons, means for introducing vapor from said dephlegmator into said tower at a point above said supporting means, means for withdrawing treated vapor from said tower at a point below the point of introduction, and separate means for draining from said tower polymers collected therein.

2. In an a paratus of the character described, a sti l, a fractionator for receiving vapors from the still, a tower for containing treating material capable of polymerizing unstable unsaturated hydrocarbons, means for passing vapors from said fractionator into contact with said treating material under superatmospheric pressure, means for refluxing polymers from said tower to said fractionator, and means for separately collecting the polymers and the treated vapors.

3. In an apparatus of the character described, a tower, a partition within said tower I forming a central treating chamber and an annular chamber communicating with said treating chamber at one end only, fluid perscribed, a tower, a partition within said tower forming a central treating chamber and an annular chamber communicating with said treating chamber at one end only, fluid permeable means within said central chamber for supporting solid treating materiahvaporizing means, means for passing vapors from said vaporizing means successively through said annular chamber and said central chamber, means for preventing passage of treating material from said central to said annular chamber and means for separately removing vapors and liquids from said central chamber.

5. In an apparatus of the character described, a still, a fractionator for receiving vapors from the still, a towerxcontaining means to support for, free drainage treating material of polymerizing unsaturated hydrocarbons, means for bringing vapor from said fractionator into indirect heat exchange relation and then into actual contact with said treating material, and means for returning from said treating tower to said fractionater polymers collected in said tower.

6. In an apparatus of the character de scribed, means for producing a vaporized hydrocarbon fraction, a tower for containing treating material ca able of polymerizing unsaturated hydrocar ons, means within sai tower to support said treating material for free drainage, means for passing said vaporized hydrocarbon fraction around the treating material in indirect heat exchange relationship and then into actual contact with said treating material, and means for separately removing liquids and vapors from said treating material.

In testimony whereof, I have signed my name to this specification.

THOMAS T. GRAY.

CERTIFICATE OF CORRECTION.

Patent No. 1,862,507. June 7, 1932.

THOMAS T. GRAY.

it is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, line 42, for "mass" read phase; page 5, line 124, claim 5, after "material" insert the word capable; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 4th day of October, A. D. '1932.

M. J. Moore,

(Seal) Acting Commissioner of Patents.

6. In an apparatus of the character de scribed, means for producing a vaporized hydrocarbon fraction, a tower for containing treating material ca able of polymerizing unsaturated hydrocar ons, means within sai tower to support said treating material for free drainage, means for passing said vaporized hydrocarbon fraction around the treating material in indirect heat exchange relationship and then into actual contact with said treating material, and means for separately removing liquids and vapors from said treating material.

In testimony whereof, I have signed my name to this specification.

THOMAS T. GRAY.

CERTIFICATE OF CORRECTION.

Patent No. 1,862,507. June 7, 1932.

THOMAS T. GRAY.

it is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, line 42, for "mass" read phase; page 5, line 124, claim 5, after "material" insert the word capable; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 4th day of October, A. D. '1932.

M. J. Moore,

(Seal) Acting Commissioner of Patents. 

